Add proof chain and set documentation to credential issuance

[bparth24]

This PR addresses #422 by clarifying how the /credentials/issue endpoint handles credentials with existing proofs as agreed upon in the 2025-05-27 call.

Background
This PR replaces PR #495, which had corrupted commit history due to a rebase issue that lost proper attribution. I apologize for my mistake - this clean branch preserves everyone's contributions with correct authorship.

Individual Contributions

• @bparth24: Add proof chain and set documentation to credential issuance
• @TallTed: contribution - Fix grammatical issues in issue credential section
• @dlongley: contribution to improve clarity and readability of existing proof scenarios

📋 Changes Made

• Enhanced Issue Credential section to document three configuration-based behaviors:

  • Proof Sets: Append proofs in parallel for cryptographic flexibility
  • Proof Chains: Link proofs sequentially for approval workflows
  • Error Handling: Reject credentials with existing proofs when configured

• Clarified instance configuration determines proof processing behavior

Note
This replaces PR #495 due to commit history corruption. All improvements are preserved here with proper attribution.

If merged it will close: #422 and replaces: PR #495. In any case PR #495 should be closed right away.

@dlongley @msporny @TallTed - ready for review & merge.

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Preview | Diff

[msporny]

@bparth24 Still not quite right, you have to make sure the author is set to the right value for each commit. Given the commits you've done, we'd have to manually go through each commit to assign provenance instead of just using the commit author field. We have a script to do the tallying automatically based on git author (not commit message, which we can't depend on because of the varied way that people do commit comments).

You will want to do something like:

git rebase -i FIRST_COMMIT_IN_PR
for each commit:
  git commit --amend --author="New Author Name <[email protected]>" --no-edit
  git rebase --continue
git push --force

Also, please use a consistent commit message format:

https://github.com/digitalbazaar/bedrock/blob/main/CONTRIBUTING.md#commit-messages

[bparth24]

@bparth24 Still not quite right, you have to make sure the author is set to the right value for each commit. Given the commits you've done, we'd have to manually go through each commit to assign provenance instead of just using the commit author field. We have a script to do the tallying automatically based on git author (not commit message, which we can't depend on because of the varied way that people do commit comments).

You will want to do something like:

git rebase -i FIRST_COMMIT_IN_PR
for each commit:
  git commit --amend --author="New Author Name <[email protected]>" --no-edit
  git rebase --continue
git push --force

Also, please use a consistent commit message format:

https://github.com/digitalbazaar/bedrock/blob/main/CONTRIBUTING.md#commit-messages

@msporny

• Thank you for reviewing and guiding me. I updated the author for each commit using your script.
• I will make sure to read the commit message format instructions a few more times before committing.
• Now, for this PR, if you want me to update the commit message as per the commit format, I'm happy to do those as well.

[msporny]

if you want me to update the commit message as per the commit format, I'm happy to do those as well.

yes, please do. Ideally, all commits should follow that format.

[bparth24]

if you want me to update the commit message as per the commit format, I'm happy to do those as well.

yes, please do. Ideally, all commits should follow that format.

@msporny I understood and updated the commit messages.

[msporny]

@msporny I understood and updated the commit messages.

Excellent! LGTM, merging.